Plum Jam with less sugar

The amount of sugar used in a traditional jam is a LOT! This method uses much less and still ends up in a tasty jam with a longer shelf-life.

Watch to see how to make Plum Jam using less sugar

Sugar is used in jam for 2 reasons (or maybe 3, if you include taste).

The first reason is that the sugar acts as the preserving agent for the fruit. It acts to prevent bacteria and other food spoilants from taking hold. The ratio needed for this is at least 75% of the weight of the fruit has to be added as sugar. Which, when you are processing a kilo of fruit, gets to be quite confronting in terms of all that sugar.

The second reason is that the sugar acts to help 'gel' the fruit. This magic happens with the combination of the fruit with its natural pectin, the sugar and the acid (again from the fruit or added as lemon juice). 

So it would add up that, without enough sugar, firstly the jam might go mouldy; and secondly, the jam won't gel and just stay very runny.

This is true to an extent but it can be overcome. 

To overcome the preserving issue, after making the jam I make sure that I heat-preserve the filled jars. This makes a great vacuum seal on the jars, which means there is no air in the jar. No air = no bacteria.

To make up for lack of a firm set, I cook it a little longer than I normally would with a full sugar jam; and then accept that it will be easier to spread on my breakfast toast than a commercial jam, whose sugar content may be even higher than the 1:1 ratio. So it might be called 'spreadable fruit' rather than a true jam.

I have also tried adding a minute amount of Xantham gum powder (available in the health food section of my local supermarket) right at the end of the cooking process, This does firm up the jam, so that it is still spreadable. But don't overdo it as you might have rock hard jam.

Always store in the fridge after opening and give yourself a little pat on the back in the morning when you have your toast with a little sweetness - but not too much!